How does Whoop track sleep?

Whoop tracks sleep by utilizing a combination of sensors within the Whoop Strap, which includes an accelerometer, gyroscope, and a heart rate monitor with PPG (photoplethysmography) sensors. These components work together to detect motion and physiological signals that indicate the wearer's different sleep stages: awake, light sleep, deep sleep, and REM sleep. By analyzing fluctuations in heart rate variability (HRV), resting heart rate, and movement throughout the night, Whoop can deduce sleep quality and cycles. Its sophisticated algorithms process this data to provide users with detailed insights into their sleep patterns, recovery status, and overall sleep performance, helping them to understand the effect of their daily activities on their rest and recovery.